1. Field of the Invention
The present invention is directed to data display. It particularly concerns effectively displaying high-dimensional data, including, but not limited to, volumetric data, e.g., medical image data, security screening data, or architectural drawing data.
2. Background Information
In recent years, it has become commonplace to use computers to obtain desired information from databases far too large for individual-human comprehension. Software has been developed for performing analysis of a highly sophisticated nature, and such software is often able to detect trends and patterns in the data that would, as a practical matter, be impossible for an individual human being to find.
The converse is often also true. Particularly when the question to be asked does not lend itself to easy definition, computers often have difficulty detecting patterns that are readily apparent to human beings. And this human capability is best brought to bear when the data in question are presented graphically. Data presented graphically usually are more readily understandable than the same data presented only in, say, tabular form. But the degree of the resultant understanding greatly depends on the nature of the display, and determining what the appropriate display should be can present a significant problem.
The way to represent many types of data, for example, volumetric medical image data, poses a significant challenge to determine. Volumetric images may be quite complex. In such images, a volume element is referred to as a “voxel” (analogous to a pixel in two-dimensional space). Depending on the transparency assigned to the voxels, graphical features that may be of interest to a viewer may be obscured by other voxels. Similarly, the complexity of volumetric images, in some fields, for example, medical imaging, result in the boundaries of various features being difficult to detect.
To help human users employ such data and images effectively, there is a need for presentation or data display systems which make important features, (e.g., patterns, structures, etc.) “stand out” from the other data presented on the display. For example, some systems employ color, line thickness, etc. to highlight graphical features which visually represent portions of the data that meet criteria of particular interest. Another approach is the use of stereo and rotating perspective displays in data display systems. However, while stereo views and rotating perspective views increase the human user's understanding of volumetric data and images, they do not by themselves make portions of the displayed image stand out from the other data presented on the display.
Another approach that may be used to display data and images is “brushing,” which is sometimes used when representations of the same data objects are displayed simultaneously in different relative locations in different displays. (The displays can be on the screens of different monitors, for example, or on different parts of a single monitor's screen.) In brushing, a user employs a mouse or other device to select a subset of the objects in one display, and the display system highlights other display's objects that represent the same objects.
Another technique, previously proposed in assisting human users to distinguish important graphical features in two-dimensional images is to impart motion to these graphical features. Such a display technique takes advantage of the inherent ability of the human perception system to recognize patterns in data by quickly associating graphical features that are moving in the same fashion.